mclean



Patented Aug. 21, 1928.

UNITED STA ES WILLIAM B. MCIIEAN, OF MONTREAL, QUEBEC, CANADA.

BURR FOR enmnsroivris.

Application filed January 17, 1927. Serial No. 161,657.

supported. in such a manner that it may be easily and conveniently replaced should it become blunt, broken or otherwise made unfit for, further service.

A further object is to provide a shell burr which will'be well supported to withst'and any excessive strains which may be exerted thereon during the use of same.

A still further object is to provide a shell burr-f and mounting therefor which will hold the burrs securely in place and in perfect cylindrical form. I [In the manufacture of shell burrs, the steel cylindrical shells are prepared by heating, carb'oni'zing and hardening same, and this operation often causes slight distortion in the outside diameter of the shell resulting in an uneven surface which decreases their efficiency in sharpening grindstones and the like.

In my invention I provide a shell burr so formed that when mounted on its supports it will be of perfect cylindrical form and will be held in place so that it is properly supported to reduce crippling of the burrs to a minimum. The burrs can be simply and easily removed and means are provided for locking the burr on its mounting.

In the drawings which illustrate one form of my invention,

Figure 1 is an end elevation of my 1mproved shell burr and mounting therefor.

Figure 2 is a sectional side elevation taken on the line 2-2 Figure 1.

Referring more particularly to the drawings, 11 designates a cylindrical shell burr having stone cutting or dressing teeth 12, of any type, formed in its outer wall. The teeth shown are of the V type profile, but it will be readily understood that any profile may be used and that spiral, diamond, or such like shaped teeth (not shown) may be formed without departing from the spirit I of the invention. The bore 13 of the shell is provided with tapered portions 14 and 15 at each end. The tapered surfaces are preferably machined for the purpose hereinafter stated. Fitting into one end 14 of the shell is the support or holder 16 which is of cylindrical form and is provided with circular flange 17 the edge 18 of which is tapered to fit snugly into the tapered end of the shell. The support extends through the shell and is provided with a reduced threaded portion 19. Mounted on the outer wall of the support 16 is the flange collar 20, the edge 21 of the flange of which fits snugly into the tapered end 15 of the bore of the shell. Locking pin holes 22 are formed in each of the flanges and toholdthe holes in alignment, the flange collar is slidably mounted on a key 23 fitting into slots or keyways formed in the wall of the support 16 and in the bore of the flanged collar. The keys also prevent. relative movement between the support and the collar. In the drawing I have shown eleven bolt holes in each flange. A threaded nut 24 is mounted on the threaded end of the supportlfi and is provided with a flange 25 having a plurality of slots 26 formed therein. The slots 26 are so positioned that they may be aligned with the'hole'sin the flanges of the collar andthe holder. In thedrawing twelve slots are shown, so that only one of the slots will be in alignment with the holes in the flanges at a time. This arrangement of slots and holes allows very fine adjustments to be made in fitting of the parts together and makes allowance for any variations which may be found in the tapered diameters of the bores of the shell. A locking pin 27 is placed through one of the slots and one of the holes in each of the flanges to hold the burrs in position. The support 16 is mounted on bushings 28, the inner surfaces of which contact with the burr supporting spindle 29.

Modifications may be made in the general construction of the device without departing from the spirit of the invention.

In assembling the device, the shell is mounted on the support 16 and the flanged collar is mounted between the inner wall of the shell and the outer wall of the support. The contacting faces of the shell and the flanges of the collar and the support are tapered and fit snugly into one another. The tapered surfaces are preferably machined so that should the bore of the shell alter during the hardening of the same, or from any cause, the flanges will press the shell so that it will be pulled into its orig inal cylindrical or machined form. The flanges of the support and the collar are pulled towards one another by the movement of the nut and when in position, the lock pin is pushed through the nut and both flanges to prevent relative circular or rotative movement between the various members of the device. It will be readily seen that the surfaces of the flanges form an efficient support for the shell and that the whole structure may be quickly and easily dismantled for repairs, replacement, and the like.

Having thus described my invention, What I claim is 1- 1. In a shell burr, a cylindrical shell hav ing stone cutting teeth formed in its outer face, the bore of the shell having tapered portions at each end, a support for said burrs, extending through the bore of same, a flange formed integral with said support and provided with a tapered edge adapted to fit into one end of the shell, a flanged collar mounted on the support, the flange of the collar being tapered to fit into the other tapered end of the bore and a nut mounted on a threaded portion of the support to hold the flanges in contact with the bore, said nut having a flange provided with peripheral slots and a pin passing through one of said slots and through aligned openings formed in the flanges of the support and collar.

2. In a shell burr, a cylindrical shell having stone dressing teeth. formed in its outer face, the bore of the shell having tapered portions at each end, a support for said shell extending through the bore of same,

a supporting flange formed integral with the support and having its edge tapered to engage with the tapered bore of the shell at one end thereof, a flanged collar slidably at a time with the holes in the flange, the

number of slots being different from the number of holes and a locking pin passing through the flanges of the nut, collar and support. v

.3. In a device of the character described the combination of a shell, a member passing through the bore of said shell, a stationary flange on said member engaging and supporting one end of the shell, a second flange slidably mounted on said member and supporting the remaining end of the shell, a nut screwed on to said member and engaging the outer face of the slidably mounted flange, said nut having a flange provided with peripheral notches adapted to be aligned with selected ones of a plurality of openings formed in the shell supporting flanges and a pin passing through one of said notches and through openings of the shell supporting flanges aligned with said notches.

In witness whereof, I have hereunto set my hand. i

WILLIAM B. MCLEAN. 

